Device for intermittent motion of second hand



Sept. 1957 M. F. NOVIKOV ETAL 3,340,687

DEVICE FOR INTERMITTENT MOTION OF SECOND HAND Filed Aug. 13, 1965 United States Patent 3,340,687 DEVICE FOR INTERMITTENT MOTION 0F SECOND HAND Mikhail Fedorovich Novikov, Ul. Pristanskaja 26; Alexandr Petrovich Ananiev, Ul. Engelsa 115, Kv. 16; and Robert Zuferovich Kulikov, Ul. Lva Tolstogo 135, Kv. 2, all of Chistopol, U.S.S.R.

Filed Aug. 13, 1965, Ser. No. 479,489 Claims. (Cl. 58-59) This invention relates to timepieces, specifically to mechanical and electric wrist watches, and more specifically to devices for intermittent motion of the second hand at intervals of one second.

The devices currently used for this purpose are complicated in design and unwieldly in construction, which hampers their application.

The object of this invention is to provide a simple device for intermittent motion of the second hand, the use of which in watches will permit of both promoting the manufacture and reducing the thickness thereof.

According to the present invention, the device for intermittent motion of the second hand comprises a springloaded movably mounted lock serving to retain the second hand in sixty consecutive positions and engaging with a sixty-tooth wheel mounted on the second hand pinion.

The lock and the wheel teeth are so shaped that the second hand, by virtue of the backlash in the toothed wheel pair connecting the second hand pinion with the drive wheel, can be rapidly moved under the action of the lock through an angle approximately the angle of locking pitch and then retained at rest for nearly a complete second.

It is expedient to arrange the proposed device so that the lock has working faces inclined at different angles With the straight line connecting the center of the sixtytooth wheel with the apex of the lock, the tips of the Wheel teeth being pointed.

Another expedient embodiment is to mount the lock on a rocking lever or to make it integral therewith. In some embodiments it will be expedient to mount the lock slidably in guides, in which case the lock should be either attached to a reciprocating part or made integral there with.

For a further understanding of the present invention reference is to be made to the following description and the accompanying drawings, wherein:

FIG. 1 is a schematic diagram of the embodiment proposed for use in mechanical wrist watches with a sweep second hand;

FIG. 2 illustrates the engagement of the lock with the sixty-tooth wheel;

FIGS. 3, 4, 5 and 6 diagrammatically illustrate possible embodiments of the lock.

The pinion 1 of the sweep second hand 2 (FIGS. 1 and 2), having a sixty-tooth wheel 3 aflixed to it, receives motion from an intermediate wheel 4 of the main gearing system. While turning, the pinion 1 brings the tip 5 of the tooth 6 of the wheel 3 to the tip 7 of the lock 8, i.e. to the point 9 where unstable equilibrium exists, the action of the pinion resulting in the lock being forced off.

By the action of a spring 10 and the working face of the lock 8, the tooth 6 of the wheel 3 and, consequently, the wheel 3 together with the pinion 1 and the second hand are rapidly advanced in an impulse motion, i.e. are brought to the subsequent position, wherein the two working faces of the lock 8 bear against the tips of the two adjacent teeth of the sixty-tooth wheel 3.

The backlash between the intermediate wheel 4 and the pinion 1 of the sweep second hand 2, as existing in 3,340t687 Patented Sept. 12, 1967 customary gearing, is nearly always suflicient for the pinion 1, hand 2 and wheel 3 to reach the subsequent locked position wherein they remain at rest until, in the process' of operation of the main gearing system, one of the teeth of the intermediate wheel 4 contacts the tooth of the pinion and causes the tip of the subsequent tooth of the wheel 3 to move past the tip of the lock, i.e. to pass the point of unstable equilibrium (point 9), whereupon the cycle is repeated.

The escape wheel 11, second wheel'12, pseudo-center wheel 13 and great wheel 14 are similar to those used in conventional watch movements.

Inasmuch as the working faces of the lock 8 are inclined at different angles with the straight line connecting the center of the sixty-tooth wheel 3 with the apex of the lock 8, the angle through which the wheel 3 turns from the first locked position to the point of unstable equilibrium under the action of the intermediate wheel 4 differs from the angle through which the wheel 3 turns from the point 9 of unstable equilibrium to the subsequent locked position under the action of the inclined working face of the lock 8.

It is expedient to incline the faces of the lock 8 so (see FIG. 2) that within back pitch 2, i.e. within the 6 angular movement from one locked position to the other, the movement of the wheel from the fixed position to the point of unstable equilibrium should be considerably less than the advance of same due to the action of the lock. If the lock faces are inclined so that the movement of the wheel from the locked position to the point of unstable equilibrium approximately equals t/6, i.e. 1, the changeover from one locked position to the other in a watch with a period of balance oscillation of 0.4 second will be nearly instantaneous, the hand remaining at rest for about a complete second. To this end it is advisable to make the tooth tips of the sixty-tooth wheel and the tip of the lock pointed as much as possible and to fabricate the lock from a material such as ruby so as to enable the working faces to be highly finished.

If the lock 8 is made as an independent part, it is expedient to mount it on a rocking lever 15 loaded by a spring 10, the mounting being similar to that employed in securing pallets in the lever fork of conventional Watches (FIG. 3).

It is possible to make the lock 8 integral with the lever 15 (FIG. 4). i

In some cases it is advantageous to mount the lock on an auxiliary part 16, provision being made for the latter to reciprocate in guides (FIG. 5

It is also possible to make the lock 8 integral with the part 16, the latter reciprocating in guides (FIG. 6).

The compression spring 10 may take various forms, of which the most expedient is a plate spring as used in the embodiments described hereinabove, or a spiral spring as used in the watch balance.

The use of the proposed device is particularly advantageous in the movements wherein the pinion of the sweep second hand is incorporated in the general kinematic chain through the use of a double intermediate wheel or is loaded by a friction (brake) spring. In the former case the double wheel should be replaced with a single one, whereas in the latter case the spring should be omitted.

The proposed device can also enable the second hand to move intermittently at intervals of 2 seconds, which is achieved by using a thirty-tooth wheel instead of a sixtytooth one.

What we claim is:

1. A device for controlling intermittent motion in a watch, comprising a second hand, a movably mounted lock adapted to move and to retain the second hand in sixty consecutive positions during one revolution; a pinion connected to the second hand, a sixty-tooth wheel attached to the pinion of said second hand and interacting with said lock, the lock having Working faces which are inclined at different angles with respect to a straight line connecting the center of said sixty-tooth wheel with the apex of said lock, the tips of the teeth of said sixty-tooth wheel being pointed in order that they may interact with said working faces of said lock so as to provide stable and unstable positions to enable the second hand to be moved rapidly through a tooth pitch angle and to be retained at rest for nearly a complete second, a wheel for driving said pinion, a toothed wheel pair coupling the latter said wheel and the pinion, rapid movement of said second hand being enabled by backlash provided in the toothed wheel pair connecting the second hand pinion with the wheel from which said second hand pinion receives motion, the backlash being of such an extent that, after the unstable position has been reached, movement to said stable position is controlled by action of the lock against said sixty-tooth wheel, the lock and teeth being cooperating elements each of which have angularly related faces connecting at a peak, the teeth on said sixtytooth wheel having each a six degree extent and one of the faces of each tooth having an extent of no more than about one degree through which the tooth must be displaced to reach the unstable position.

2. A device as claimed in claim 1, comprising a rocking lever and wherein the lock is mounted on the rocking lever.

3. A device as claimed in claim 2, wherein the lock is integral with said rocking lever.

4. A device as claimed in claim 1, comprising guides and a part adapted for reciprocating movement in said guides and wherein the lock is mounted on the part adapted for reciprocating movement in the guides.

5. A device as claimed in claim 4, wherein the lock is made integral with said part adapted for reciprocating movement.

References Cited UNITED STATES PATENTS 2,591,876 4/ 1952 Robert-Charrue 5859 2,632,293 3/1953 Meyer 5858 2,766,578 10/ 1956 Robert-Charrue 5 859 2,817,207 12/1957 Beyner 5828 3,058,293 10/1962 Egger 5859 RICHARD B. WILKINSON, Primary Examiner.

GERALD F. BAKER, Examiner.

M. LORCH, Assistant Examiner. 

1. A DEVICE FOR CONTROLLING INTERMITTENT MOTION IN A WATCH, COMPRISING A SECOND HAND, A MOVABLY MOUNTED LOCK ADAPTED TO MOVE AND TO RETAIN THE SECOND HAND IN SIXTY CONSECUTIVE POSITIONS DURING ONE REVOLUTION; A PINION CONNECTED TO THE SECOND HAND, A SIXTY-TOOTH WHEEL ATTACHED TO THE PINION OF SAID SECOND HAND AND INTERACTING WITH SAID LOCK, THE LOCK HAVING WORKING FACES WHICH ARE INCLINED AT DIFFERENT ANGLES WITH RESPECT TO A STRAIGHT LINE CONNECTING THE CENTER OF SAID SIXTY-TOOTH WHEEL WITH THE APEX OF SAID LOCK, THE TIPS OF THE TEETH OF SAID SIXTY-TOOTH WHEEL BEING POINTED IN ORDER THAT THEY MAY INTERACT WITH SAID WORKING FACES OF SAID LOCK SO AS TO PROVIDE STABLE AND UNSTABLE POSITIONS TO ENABLE THE SECOND HAND TO BE MOVED RAPIDLY THROUGH A TOOTH PITCH ANGLE AND TO BE RETAINED AT REST FOR NEARLY A COMPLETE SECOND, A WHEEL FOR DRIVING SAID PINION, A TOOTHED WHEEL PAIR COUPLING THE LATTER SAID WHEEL AND THE PINION, RAPID MOVEMENT OF SAID SECOND HAND BEING ENABLED BY BACKLASH PROVIDED IN THE TOOTHED WHEEL PAIR CONNECTING THE SECOND HAND PINION WITH THE WHEEL FROM WHICH SAID SECOND HAND PINION RECEIVES MOTION, THE BACKLASH BEING OF SUCH AN EXTENT THAT, AFTER THE UNSTABLE POSITION HAS BEEN REACHED, MOVEMENT TO SAID STABLE POSITION IS CONTROLLED BY ACTION OF THE LOCK AGAINST SAID SIXTY-TOOTH WHEEL, THE LOCK AND TEETH BEING COOPERATING ELEMENTS EACH OF WHICH HAVE ANGULARLY RELATED FACES CONNECTING AT A PEAK, THE TEETH ON SAID SIXTYTOOTH WHEEL HAVING EACH A SIX DEGREE EXTENT AND ONE OF THE FACES OF EACH TOOTH HAVING AN EXTENT OF NO MORE THAN ABOUT ONE DEGREE THROUGH WHICH THE TOOTH MUST BE DISPLACED TO REACH THE UNSTABLE POSITION. 